Method of casting



H. A..SCHWARTZ.

METHOD 0F CASTING.

APPL'lcATIoN F|LED1uNE6.1921.

Patented Sept lmz'll/ Harryjl. Sehwariz ATTORNEYS `metal, such for examp Patented Sept. 12, 1922.

UNITED 'STATES HARRY A. SCHWARTZ, @F DEFIANCE, OHIO.

METHOD OF, CASTING.

.Application ma .rune-s, mi. semi No. 475,968.

To all whom t may concern:

Be it known that I, HARRY A. SCHWARTZ,

a citizen of the United States, anda resi-y dent of Defiance, in the county of Defiance and State of Ohio, have invented a new and Improved Method of Casting, of which the following is a full, clear, and exact description.

This invention relates to improvements in method of casting, and more particularly to an improved method of casting in permanent molds, an object of the invention being to maintain within a constant range, the temperature of the mold during the casting operation and between casting operations where the molds are used continuously, so that uniform castings may be made in permanent molds without material or injurious deterior ion of the mold itself.

l am, of course, aware that' it is old in the art of casting to cast in permanent molds and it is also old to chill or cool molds, but I believe that I am the first to cast in molds where the mold is maintained within a constant range of temperature.

The art of casting in permanent molds has been developed extensively in the low melting alloy metal field by the die casting process; that is, forming castings of alloy metal in metal dies by placing the metal in the dies under pressure. The cause of the development of this particular field is due to the fact that alloys of comparatively low melting temperature are used, the dies or molds not being subjected to the comparatively extreme temperatures which are necessary in the metal group, such as iron, etc.

When permanent molds, such as in ordinary use, are subjected to extreme heat and allowed to cool repeatedly, they will deteriorate to a more or less rapid extent. Also after pouring for a time, the molds be- .come very hot, so that castings cannot be made in as frequent intervals as when the molds were cooler. Furthermore, the physical properties of e as iron castings, are improved considerably when cast in permanent molds. When cast iron sets from the molten stage, the elements which make upthe cast iron composition tend to segregate to a large extent. If this segregation is prevented, the physical properties are improved, and it is the purpose of my invention to provide a method of casting whereby the temperature of the molds is controlled, so that this segregation can be prevented in so far as it is desirable to do so.

With ordinary permanent molds, when the cast' iron is poured in, the heat from the molten metal is'extracted very quickly, depending on the size of the casting made. Segregation in this way is largely prevented,

, the metal setting so quickly that segregation cannot take place to a large extent, but permanent molds, such as ordinarily made, do not have any control of temperature, but rely solely upon a reduction of temperature or a carrying away of the heat units by radiation or chilling. The problem, therefore, of casting in permanent molds resolves itself into the question of first quickly takv ing away from the mold the heat that it has takenfrom the casting made in it until the casting is set', and then maintain a comparatively uniform temperature for a desired length of time and allowing the metal to cool as gradually as may be desired, and I can accomplish this purpose in molds of the same metal as the castings without danger in any way of injuring the mold, but, on the other hand, permitting a repeated use of the mold.

In casting in permanent molds, the following five factors governto a large extent the process of casting in permanent molds:

l. Temperature control of the molten iron at the pouring.

2. Controlling the molten iron stream, as to cross-section and flow, when entering the mold.

3. Maintaining the mold at an even and constant temperature.

4f.V Controlling the ejection of the casting on its completion.

5. Preserving the physical condition of the mold.

All of these factors must be considered to produce the best results, but in the present application emphasis is particularly laid upon the third element maintaining the mold at an even and constant temperature and the fifth element preserving the physical condition of the mold.

A further object is to provide a method of the character stated,lwhich not only results in the making of superior castings, but which len hens the life of the mold and increases t e output or effectiveness of the mold operation.

iWith these and other objects in View the invention consists in certain novel features of the mold and means and steps in the operation of controlling the temperature of the mold during the casting operation, as will be more fully hereinafter described and pointed out in the claims.

In the accompanying drawings- Figure 1 is a view showing more or less diagrammatically an apparatus in which my improved method of casting can be carried out.

Figure 2 is a view in longitudinal section through the mold.

I would have it understood that this invention is not limited to any particular form of mold or mold support, although it is to be understood that the mold will be preferably of metal, comprising two or more sections 1 and 2 having a mold space 3 between them in which the casting 4 is formed. The mold. sections 1 and 2 are hollow form-ing fluid chambers 5 and these fluid chambers may be arranged and shaped in any desired way to give the best results.

In carrying out my improved method I preferably employ a storage tank 'or reservoir 6, from which 'the fluid is forced by means of a pump 7 through a pipe 8 and branch pipes 9 and 10 into the fluid chambers 5 of the upper and lower mold sections. In this pipe 8 and in the branch pipes 9 and 10 I provide manually operated valves 11, 12' and 13 respectively, so that the flow of fluid to the mold sections can be controlled.

14 represents a refrigerating device of any approved construction, and` I do not wish to be limited to the arrangement of tank shown and may employ any refrigerating device desired. Branch outlet pipes 15 and 16 communicate with the upper and lower mold sections 1 and 2 respectively and discharge into a pipe 17 communicating with the condenser tank 14 and a pipe 18 connects the condenser tank 'with the storage tank 6, so that a circulation may be maintained or cut ofi' as desired.

While I have illustrated in the drawings as a refrigerating or temperature controlling medium a liquid, it is obvious that I ma employ and fluid, either gas or liquid, whic will perform the functions intended.

It isto be understood that the system is preferably full of the fluid so that when the pump 7 is operated, the fluid will be caused to circulate through the system as rapidly as the position of the valves 11, 12 and 13 will permit.

In carrying out the method the vmolten I metal is poured into the mold and it is preferable at the initial pouring to have the valves 11, 12 and 13' wide open so that a maximum of flow ofthe cooling agent will be had through the chambers 5 of the mold section vto rapidly coolthe casting. When this rapid cooling accomplishes the purpose of preventing segregation of the elements of the casting, the flow is cut down by partially closing the valves, and may be cut down as much as desired to maintain the temperature or permit a slow decline in temperature to cool the casting as slowly or as vquickly as desired, or to maintain it at a certain temperature for a period of time and then cool it, all of which temperature regulation is under the control ofthe operator by simply manipulating the valves 11, 12 and 13.

It is, therefore, apparent that in carrying out my improved method of casting, the temperature regulation above referred to, not only includes a reduction of temperature, but the rapidity of such reduction of temperature, and hence the element of time enters into the operation, so that the temperature can be maintained or decreased as desired and always under the control of the operator. i

It is to be understood that by temperature regulation I not only include by such a definition a reduc-ing of'temperature, but more particularly, means whereby the mold sections may be maintained at a constant temperature for the desired length of'time.

In carrying out my improved method of casting in permanent molds, whereby temperature of the molds is regulated, I employ a closed.temperature-controlling fluid circuit with means in the circuit for establishing a desired temperature for the Huid and with means in the circuit for controlling the amount of fluid in transit. Figure 1 illus-- trates clearly the closed circuit; 14; represents the means for establishing a desired `temperature for the fluid and they valves 11, 12 and 13 indicate the means for controlling the amount or quantity of fluid in circuit to and through the molds. Without these elements I am convinced that no proper temperature regulation can be had in a casting. In carrying out my improved method with such means I am enabled to reduce the temperature of the mold and the casting as rapidly as desired, maintain the temperature uniform or gradually decrease the same as may be desired, so that there may be in truth and in fact a real temperature regulation.

The last step in, the method where it is desired to obtain` smooth finished castings without machining, is to inject the casting into an asbestos powder which will prevent l surface oxidation.

It is obvious that the invention is not limited to the particular apparatus above described, as I desire to cover broadly the idea of temperature regulation for moldsof the type set forth, whereby a casting is formed which I believe is an improvement in the art, and furthermore, I believe the entire operation of casting in accordance with my method results in economy and in better results to the trade. Y

I claim:

1. The hereindescribed method of casting, consisting in introducing molten metal into a mold, andmaintaining the mold Within a constant range of temperature.

2. The hereindescribed method of casting, consisting in providing a pair of permanent mold members, introducing molten metal between the mold members, and maintaining the mold Within a constant range of tem` perature. l

3. The hereindescribed process of casting, vconsisting. in casting mplten metal in a per.- m'anent mold of the same metal as the casting, said mold members having chambers therein, and during the process of cooling the casting in the mold, maintaining the ,mold Within a constant range of tempera-A ture,`by the movement of the fluid through the chambers.

4. The hereindescribed consisting bers having iuid chambers therein, intro-= ducingmolten metal between the mold members, causing a circulation of a-cooling Huid through said chambers, and controlling the flow of saidfluid to maintain the mold Within a constant range of temperature.

5. The herein described method of casting, consisting in casting in a permanent mold, and during thetime the casting is in the mold and after the casting is ejected from the mold, maintaining a constant range of temperature of the mold.

HARRY A. SCHWARTZ.

method of casting, in providing a'lpair of mold mem-l 

